Russia's Foreign Minister Sergei Lavrov, second left, is escorted through "The Holocaust: Annihilation, Liberation, Rescue" exhibit, by Yuri Kanner, left, president of the Russian Jewish Congress, and Ilya Altman, right, founder and co-chairman of the Russian Research and Educational Holocaust Center in Moscow, Thursday, Jan. 18, 2018, in the United Nations visitors lobby. (AP Photo/Richard Drew)

Irena Petruck, originally from western Ukraine, adjusts the uniform epaulet of Igor Tokar, originally from Vinnitsa, Ukraine, as they visit "The Holocaust: Annihilation, Liberation, Rescue" exhibit in the United Nations visitors lobby, Thursday, Jan. 18, 2018. (AP Photo/Richard Drew)

UNITED NATIONS (AP) — Russian Foreign Minister Sergey Lavrov opened an exhibition on the Holocaust in the former Soviet Union on Thursday, saying the world has "a sacred duty" not only to commemorate the millions of victims "but to do everything in our power to prevent such tragedies in the future."

He called the Holocaust "one of the worst crimes against humanity" and said it was troubling "that recently we see the creeping rehabilitation of Nazis."

In a number of unnamed countries that consider themselves "paragons of democracy," Lavrov said there are systematic efforts to revise the outcome of World War II including glorification of the activities of Germany's wartime leader Adolf Hitler and local collaborationists.

He called it "especially immoral" that some European Union members are destroying monuments to Soviet soldiers, who paid with their lives to rid the world of the Nazi horrors and help ensure peace and stability on the European continent.

"Such actions are a sacrilege from the common human standpoint," Lavrov said. "We all should decisively counter such very dangerous trends."

After Germany's invasion of the Soviet Union on June 22, 1941, the extermination of Jews began.

According to one panel in the exhibition, "2.7 million people were shot, burned, buried alive, drowned in rivers and swamps, hanged." All were Soviet citizens, and they represent almost half of all Holocaust victims, it said.

The exhibition, entitled "The Holocaust: Annihilation, Liberation, Rescue," includes documentary evidence and photographs of prisoners of Nazi death camps and their liberators — soldiers of the Red Army.

It opened ahead of International Holocaust Remembrance Day on Jan. 27, the anniversary of the Soviet Army's liberation of the Auschwitz concentration camp in Poland in 1945 by Soviet troops.